Steam-engine governor



Patented Jen. 11, 1887.

Mad/v (No Model.

' Ii-M; RITES; v I STEAM ENGINE GOVERNOR- NO. 355,717.

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UNTTED STATES PATENT @FFICE,

FRANCIS M..RITES, or PITTSBUBG, PENNSYLVANIA.

STEAM-ENGINE GOVERNOR.

fiPECIPICAT-ION forming part of Letters Patent No. 355,717, dated January 11, 1887.

Application filed September 1,1880. Serial No. 212,351. (X0 model.)

To all whom it may concern.-

Be it known that I, FRANCIS M. Burns, residing at Pittsburg, in the countyof Allegheny and State of Pennsylvania, a citizen ofthe United States, haveinvented or discovered certain new and useful Improvements in Steam- Engine Governors, of which improvements the following is a specification.

My invention relates to automatic cut off governors of the class which are mounted upon the main or crank shaft of the engine and effect regulation by variation of the position of an adjustable eccentric actuatinga valve which governs the supply of steam to the cylinder; and its object is to provide a governor specially adapted to engines having their distribution-valves reciprocating in substantially ver tical planes, in the employment of which, under a simplified and economical construction, the gravity of the eccentric andv of the reciprocating parts shall be effectively counterbalanced and the weight of the eccentric reduced to the minimum compatible with required strength, I

To this end my invention, generally stated, consists in the combination of an adjustable eccentric or crank-pin pivoted upon a crankshaft, and coupled to a valve reciprocating in a substantially vertical plane, anda governorweight pivoted upon the crank shaft and coupled to theeccentric in such manner as to move in opposite direction thereto.

The improvements claimed are hereinafter fully set forth.

In previous constructions of the class to which my invention relates the gravity of the reciprocating partshas been balanced by provision for the exertion of an upwardlyacting force, and it has ordinarily been necessaryto employ two governor weights coupled together and pivoted at opposite points toasupporting member on the shaft, so as to balance each other as well as to counterbalance the eccentric by a corresponding weight.

I am further aware that governors having but a single weight, the gravity of "which is counterbalanced by that of the eccentric, have been heretofore known and used; but such require a comparatively heavy eccentric and are incapable of effective operation with a vertically-reciprocating valve without the provision of a special balancing device for grav ity of the reciprocating parts. Under my invehtion such balance is effected by the gravity of the single weight, and the eccentric, being freed from balancing function, may-be made as light as its strength will permit, or a single crank-pin may be employed in its stead.

In the accompanying drawings, Figure 1 is a vertical transverse section through a steamengine, taken at the center of the valve-chest, showing a face View of a governor embodying myinvention; Fig. 2, a side view in elevation ofthegovernor; Fig. 3, aface view ofthecrankarm, illustrating more fully the positions of.65 the pivots of the eccentric and weight; and Fig. 4, a similarview of the same with the weight and spring attached.

The engine in which my invention is herein shown as applied is of the vertical single-act- 7o ing type, having its cylinders 1 secured upon the top of a crank case or box, 3, provided with proper end bearings for a crank shaft, 5, having double cranks 2, to the pins i ofwhich the pistons of the cylinders 1 are coupled by connecting-rods. The admission and exhaust of steam to and from the cylinder 1 is effected by a distribution-valve, 7, composed of an up per piston, 8, and a lower piston, 9, fixed upon a valve-stem, 10, which is adapted to recipro- 8o cate in a sleeve or bushing, 11, provided with proper steam and exhaust ports, and fixed in a valve-chest, 12, located between the cylinders 1, and slightlyinclined relatively thereto, such construction being one of the numerous types of vertical engines to which my improvements are desirably applicable.

In the practice of my invention the distribution-valve 7 is reciprocated by an eccentrio, 13, the strap 19 of which is secured to one end of an eccentric-rod, 20, whose opposite end is coupled by a pin, 21, to the valve 7, the throw of said eccentric being varied as required in the operation of the engine by adjustment of its position relatively to the crankline, in order to vary the travel of the valve, and consequently the degree of expansion or point of cut off, as presently to be described.

A crank pin coupled to the lower end of the eccentric-rod would perform as an equivalent the function of the eccentric.

. The ecccentric 13 is made as light as may suffice to afford sufficient strength, being, as j shown, a simple ring formed in halves or sections, bolted together for convenience of application, and having an arm or lug, 15, on one of its sections, which is pivoted by a pin, 16, to the arm of one of the cranks 2 of the crankshaft 5.

It will be seen that by movement oftheec centric in one or the other directionabout the axis of its pivot 16 its throw, and consequently the degree of traverse which it imparts to the valve 7, is increased or diminished, as the case may be, such movement be-' ing imparted to the eccentric by the tension of a spring, 14, or the centrifugal force of a governor-weight, 26, as either maypreponderate under varying conditions of pressure or resistance, or both.

A single governor-weight, 26, is pivoted by a pin, 17, to an extension of the crankarm 6, and is coupled directly by a link, 18, to. the lug 15, which receives the pivot 16 of the eccentric, the relation of the pivots 16 and 17 of the eccentric and weight to the link 18 being such that the eccentric and weight are compelled to move in opposite directions, and the gravity of the reciprocating partsto wit, the eccentric-rod and valvewhich are connected to the eccentric is exerted in opposition to that of the governor-Weight-that is to say, downward or.ou tward movement of the weight induces corresponding upward movement of the eccentric and reciprocating parts, and vice versa. The direct connection of the governor'weight and'eccentric by the single link 18 enables the gravity of the governor-weight to be made available as a counter-balance to that of the reciprocating parts of the valve-motion in any and all positions assumed by the weight under the influence of centrifugal force.

In the construction shown the eccentric and governor-weight are pivoted to the crankarm on opposite sides of the shaft; but such location is not an essential one, as both might be pivoted on the same side, and by suitable connections to anintermediate sleeve the balancing action of the governor-weight and the reciprocating parts could be equivalently provided for.

The rule which governs the location of the pivots of the eccentric and of the governorweight, respectively, is that the angle formed by a line drawn from the center of the shaft through the center of the eccentric pivot to the line of valve travel with a vertical line shall be equal to the angle formed by a line drawn from the center of the weight-pivot to the center of gravity of the weight with the line of valve travel-that is to say, when a line drawn through the center of the shaft and center of the eccentric pivot coincides with the line of valve travel, the center of gravity of the weight shall be in line vertically with the center of the weight-pivot.

The outward movement of the weight 26 tipon its pivot 17, under the influence of cenrifugal force, by which the throw of the eccentric -is reduced, is opposed by the tension of a helical spring, 14, by which the throw of the eccentric and travel of the valve are increased in accordance with increase of load or diminution of pressure, or both, as from time to time required. The spring 14 bears at one end against an abutment, 22, on the crankarm, and at the other against a stop, 23, on a pin, 24, which passes freely through an opening in the crank-arm, and is coupled to the weight 26. The tension of the spring 14 may be varied by the adjustment of a nut, 25, engaging a screw thread on the pin 24, and forming an abutment for the stop 23.

My invention, in addition to simplifying and reducing the cost 'of an automatic cut-off mechanism, possesses the further advantage of presenting the same in such form as to be readily adaptable to operation within the contracted compass of a closed crank-case. The substantial reduction of weight of the eccentrio and the permissible substitution of a light crank-pin renders a counterbalance unnecessary, and the gravityof the reciprocating parts is fully balanced in all positions of the valve by that of the governor-weight.

I claim as my invention and desire to secure by Letters Patant 1. The combination of a distribution-valve adapted to reciprocate in a substantially vertical plane, an eccentric or crank'pin pivoted upon a crank-shaft and coupled to the distribution-valve, and a single governor-weight pivoted upon the crank-shaft and coupled to the eccentric, the pivots of the eccentric and of the governor-weight being relatively lo cated, as described, so that the gravity of the reciprocating parts of the valve-motion shall be counterbalanced by that of the governorweight, substantially as set forth.

2. The combination of a crank-arm, an eccentric pivoted thereto on one side of the axis of the crank-shaft, a governor-weight pivoted thereto on the opposite side of the axis of the crank-shaft, adirect link-connection coupling the governor-weight and eccentric on the side of the crank-shaft farthest from the free end of the weight, and a spring bearing against the crank-arm and against the governorweight, substantially as set forth.

In testimony whereof I have hereunto set my hand.

FRANCIS M. RITES. Witnesses:

J. SNowDEN BELL, R. H. VVHI'r'rLEsEY;

ICC

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